Synthesis of SrTiO<sub>3</sub> Nanoparticles by a pH-Varying Sol-Gel Process

Abstract

SrTiO3 is one of the most technologically important dielectric ceramics. In this paper, SrTiO3 nanoparticles were synthesized by a simple sol-gel route using NaOH to adjust the pH of the system. Three different strontium-containing starting precursors (Sr(NO3, SrCl2.6H2O and Sr(CH3COO)2.0.5H2O) were employed. Thermogravimetric analysis (TGA) showed complete decomposition of organics at approximately 800°C; this temperature was chosen as a calcination temperature. At 800°C, 6 hours, only the nitrate route with pH = 10 gives single-phase SrTiO3. Other conditions yield various impurities, most likely due to the incompletion of the reaction although they still contain very broad XRD peaks corresponding to SrTiO3, signifying the probable phase formation capability at these conditions. The obtained SrTiO3 powders are in the nanoscale range of 10 to 40 nm with isotropic morphology.